1. Field of the Invention
The present invention generally relates to computer systems and more particularly to a file manager for managing a plurality of files when it is required to store several versions for said files.
2. Description of the Related Art
In a computer system, a file manager shows where a file, which is commonly identified by a path, is physically located. Such a path is composed of a logical unit, a directory and a file name. The logical unit is generally referenced by a capital letter followed by a colon (e.g., C:). A directory gathers several files that have common characteristics. A classification is thus defined for the plurality of files linked to a same logical unit. Furthermore, a directory can be subdivided into subdirectories, which can themselves be subdivided into sub-subdirectories and so on. The term xe2x80x9cdirectoryxe2x80x9d will be used hereinafter with its generic meaning (e.g., referring to the whole hierarchy of the classification).
A file has a file name (e.g., FILE1). When FILE 1 belongs to the directory DIR1 linked to logical unit C:, it is identified by the path C: DIR1 FILE1. The directory and the file name represent an identifier which means that the file FILE1 is identified by a logical unit C: and the identifier  DIR1 FILE1.
The file manager therefore indicates that the file C: DIR1 FILE1 is on a definite physical unit 3X (e.g., a hard disk drive).
Now assume that the computer is provided with a standard software such as a word processing software. Naturally, all the files of this software are known by the file manager. Then, further assume that a new version of this standard software should be implemented in the computer. This new version comprises files that have the same name as files of the previous version. According to a first solution, the operating system of the computer will store such a file of the new version in the file of the previous version, since they have the same identification. However, a problem arises that when these two files are different, a malfunction could occur when operating a program or an application file that needs the previous version of the standard software.
According to a second solution, the operating system of the computer will change the ES identification of the new file in order not to delete the previous file. For example, the file SETUP of the previous version was identified as F: INSTALL SETUP and the corresponding file of the new version is now identified as F: SETUP SETUP. If a third version of the same standard software is installed, this could lead to another file identified for instance as F: INSTALL SETUP SETUP. However, a problem arises that when these three files are identical, there is a useless duplication, increasing the memory required for storing the software. Further, it is not possible to delete one of these files since some programs or application files know only F: INSTALL SETUP, other ones know only F: SETUP SETUP and the most recent ones know only F: INSTALL SETUP SETUP.
In view of the foregoing and other problems, disadvantages, and drawbacks of the conventional computer system file managers, an object of the present invention is to provide a structure and method for a file manager that stores in records all the files required by a computer and that avoids any duplication.
In accordance with the present invention, a file manager is provided for locating a file identified by a path referring to a logical unit and an identifier, the file manager comprising a table associating the file with a priority list of physical units. Thus, several versions of a file with a common logical identification can be saved. In order to have access to any one of these versions, the file manager comprises a unit for modifying the priority list.
Preferably, the table also defines attributes (Read, Write, Hide, Execute) for each item of the priority list. In this case, according to an advantageous feature, the table defines for the file a physical unit with a write attribute that differs from a physical unit with a read attribute. In addition, the file manager comprises a unit for modifying the attributes.
In a preferred embodiment, the file manager is incorporated into the controller of peripheral devices in a computer system. Alternatively, the file manager is incorporated into the operating system of a computer system.
The present disclosure relates to subject matter contained in European Patent Application No. 99480001.9, filed Jan. 29, 1999, which is expressly incorporated herein by reference in its entirety.